Rechargeable vacuum cleaner

ABSTRACT

A rechargeable vacuum cleaner comprises a main body, at least two sets of rechargeable batteries for driving a motor in the main body and a power-supply control unit. The power-supply control unit is coupled with the sets of rechargeable batteries and the motor for affecting a set of rechargeable batteries of higher voltage to supply power to the motor and for preventing the set of rechargeable batteries charging another set of rechargeable batteries of lower voltage. The power-supply control unit includes a silicon assembly (being a bridge rectifier) or a diode. The rechargeable vacuum cleaner can be of two piece type (with a detachable unit) or a two piece type. Therefore, the rechargeable vacuum cleaner can lengthen the operating time and prevent damaging the batteries.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to rechargeable vacuum cleaners, more particularly to a rechargeable vacuum cleaner utilizing the technique of voltage dividing to lengthen the operating time and the lifespan of its batteries.

(b) Description of the Prior Art

The majority of the rechargeable vacuum cleaner of prior art use a set of rechargeable batteries connected in parallel to supply a motor, such as four 12V 1300 mA batteries with an output voltage of 4.8V. The motor is then used to provide an effect of vacuum cleaning. As shown in FIG. 1, the electric circuit of a rechargeable vacuum cleaner of the prior art comprises a charging circuit and a power supplying circuit attached with a set of rechargeable batteries for powering a motor. The power supplying circuit further includes a switch for controlling charging and power-supplying of the set of rechargeable batteries. The operating time of the vacuum cleaner is determined by the power capacity of the set of rechargeable batteries divided by the electric current to the motor. Therefore, a rechargeable vacuum cleaner with only one set of rechargeable batteries has a short operating time, and continuously charging the set of rechargeable batteries is necessary for continuously using the rechargeable vacuum cleaner. Accordingly, electric resistors are used to reduce the current supplied to the motor when the electricity storage is low in the set of rechargeable batteries, whereby the operating time of the cleaner can be lengthened. However, this design cannot solve the problem of short lifespan of a set of rechargeable batteries substantially.

The problem of short lifespan of sets of rechargeable batteries occurs especially in rechargeable vacuum cleaners having more than one set of rechargeable batteries. As shown in FIG. 2, a rechargeable vacuum cleaner of the prior art has two sets of rechargeable batteries 5, 6 respectively for the main body and the detachable part. When the two pieces are combined, both of the sets of rechargeable batteries are used for power supply. When the detachable part is used alone, the set of rechargeable batteries 5 is used to drive a motor therein. Therefore, after using the detachable part for a while, the set of rechargeable batteries 5 will have an electricity capacity lower than that of the set of rechargeable batteries 6. When the main body and the detachable part are recombined, the sets of rechargeable batteries will be mutually charged due to the imbalance. This effect will gradually damage the batteries and therefore shorten the lifespan of the rechargeable vacuum cleaner. As shown in FIG. 3, a rechargeable vacuum cleaner of one-piece type having two sets of rechargeable batteries that may differ in electricity capacity; the charging from the set of higher capacity to the lower capacity is also inevitable.

SUMMARY OF THE INVENTION

Accordingly, the primary objective of the present invention is to provide a rechargeable vacuum cleaner utilizing the technique of voltage dividing realized by disposing a silicon assembly or diode between two sets of rechargeable batteries to prevent the sets of rechargeable batteries from mutual charging due to electricity capacity imbalance and therefore to lengthen the lifespan of the sets of rechargeable batteries.

The secondary objective of the present invention is to provide a rechargeable vacuum cleaner that utilizes the technique of voltage dividing over at least two sets of rechargeable batteries for lengthening the operating time of the rechargeable vacuum cleaner. The technique will not change the output voltage to the motor but can properly control the processed of charging and discharging for preventing damaging the sets of rechargeable batteries.

To achieve the above objectives, a rechargeable vacuum cleaner according to the present invention comprises a vacuum cleaner main body, at least two sets of rechargeable batteries, a motor for driving the function of vacuum cleaning and a power-supply control unit.

The power-supply control unit is coupled to the sets of rechargeable batteries and the motor, whereby the charging to the set of rechargeable batteries of relatively low electricity capacity by the set of rechargeable batteries of high electricity capacity will be prohibited.

The above-mentioned coupling between the power-supply control unit, the sets of rechargeable batteries and the motor is specifically the electric connection of the positive polarity of the sets of rechargeable batteries to one terminal of the motor via the power-supply control unit, and the electric connection of the negative polarity of the sets of rechargeable batteries to the other terminal of the motor.

To achieve the same objectives, the rechargeable vacuum cleaner further comprises a charging unit and a switch. The charging unit is connected to the power-supply control unit for charging the sets of rechargeable batteries. One terminal of the switch is connected to the negative polarity of the sets of rechargeable batteries, and the other terminal to the motor, whereby the switch can either charge or discharge the sets of rechargeable batteries.

Further, the power-supply control unit includes a silicon assembly or a diode; the silicon assembly can be a bridge rectifier.

The present invention has the advantages as follows. The installation of more than one set of rechargeable batteries using the technique of voltage dividing can lengthen the operating time of the rechargeable vacuum cleaner. Further, the sets of rechargeable batteries will be so managed that all of them can supply power to the motor, even their respective electricity capacities are different, and that mutual charging among the sets of rechargeable batteries due to the capacity imbalance will be avoided, therefore enhancing the durability of the batteries.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit diagram of a rechargeable vacuum cleaner of the prior art.

FIG. 2 is a perspective view of a rechargeable vacuum cleaner of two-piece type of the prior art.

FIG. 3 is a perspective view of a rechargeable vacuum cleaner of the prior art.

FIG. 4 illustrates the principle of the technique of voltage dividing of the present invention.

FIG. 5 is an exploded perspective view of a preferred embodiment of the present invention, which is a two-piece type.

FIG. 6 indicates the electric connection between the main body and detached piece.

FIG. 7 is a perspective view of a one-piece type rechargeable vacuum cleaner of the present invention.

FIG. 8 is a perspective view of a two-piece type rechargeable vacuum cleaner showing the location of a PCB control and a local enlarged view of the PCB control thereon.

FIG. 9 is a perspective view of a one-piece type rechargeable vacuum cleaner showing the location of a PCB control and a local enlarged view of the PCB control thereon.

FIG. 10 is a local enlarged view of the PCB control of the two-piece type rechargeable vacuum cleaner in FIG. 8.

FIG. 11 is a local enlarged view of the PCB control of the one-piece type rechargeable vacuum cleaner in FIG. 9

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawings.

The objective of the present invention is using the technique of voltage dividing to rechargeable vacuum cleaners equipped with more than one sets of rechargeable batteries, whereby the input voltage of the motor is kept constant when: (1) one of the sets of rechargeable batteries is used alone; (2) two sets of rechargeable batteries are used together; and (3) there is an imbalance in electricity capacity over the sets of rechargeable batteries.

Referring to FIG. 4, the positive-polarity terminals of two sets of rechargeable batteries BT1, BT2 are connected to a terminal of a motor through a power-supply control unit, selected from a silicon assembly and a diode. The negative-polarity terminals of the sets of rechargeable batteries BT1, BT2 are connected to the other terminal of the motor. Further, the rechargeable vacuum cleaner includes a charging unit and a switch SW. The charging unit is connected to the power-supply control unit and for charging the sets of rechargeable batteries BT1, BT2 through the power-supply control. One terminal of the switch SW is connected to the negative-polarity terminals of the sets of rechargeable batteries BT1, BT2, whereas the other terminal is connected to the charging unit or the motor M. Thereby, the sets of rechargeable batteries BT1, BT2 can be switched to a charging state. When the voltage across set of rechargeable batteries BT1 is higher than that of set of rechargeable batteries BT2, the voltage across side 2 of the silicon assembly will be higher than the voltage across side 3, thereby causing a cutoff at the diode on side 3. Therefore, the set of rechargeable batteries BT2 will not charge the set of rechargeable batteries BT1. When the voltage across set of rechargeable batteries BT2 is higher than that of set of rechargeable batteries BT1, the voltage across side 2 of the silicon assembly will be higher than the voltage across side 1, thereby causing a cutoff at the diode on side 1. Therefore, the set of rechargeable batteries BT1 will not charge the set of rechargeable batteries BT2. When the voltage difference between the sets of rechargeable batteries BT1, BT2 vanishes, there will be a voltage drop between 0.7 and 1.1V, whereby both of the sets will supply power and not charge each other.

When the rechargeable vacuum cleaner is activated, the voltage dividing circuit will automatically switch between the sets of rechargeable batteries according to the current voltage across each of the sets of rechargeable batteries, whereby the load of power supply, as well as charging, is uniformly distributed by the sets.

Referring to FIGS. 5 and 6, a preferred embodiment of the present invention as a rechargeable vacuum cleaner of two-piece type comprises a main body A and a detachable unit B, wherein sets of rechargeable batteries 5 and 6 are respectively installed and the electrically connecting terminals 9 and 10 are respectively attached. When the main body A and the detachable unit B are united, both of the sets of rechargeable batteries are supplying power. When the detachable unit B is separated from the main body A and used alone, the set of rechargeable batteries 5 supplies power to the motor. After being used for a while, the set of rechargeable batteries 5 will have a lower electricity capacity.

When the detachable unit B and the main body A are reunited, the silicon assembly will select the set of rechargeable batteries 6, now with a higher voltage to supply power till its voltage falls below that of the other set of rechargeable batteries. The silicon assembly then switches to the other set of rechargeable batteries. Thereby, the operating time of the rechargeable vacuum cleaner will be lengthened.

More specifically, the rechargeable vacuum cleaner of two-piece type is characterized by that the detachable unit B and the main body A have respective sets of rechargeable batteries 5, 6. When the detachable unit B is used for a while, the electricity capacity of the set of rechargeable batteries 6 of the main body A is still full, and it will be used first, controlled by the voltage dividing circuit, when the detachable unit B and the main body A are reunited.

Referring to FIG. 7, a rechargeable vacuum cleaner of one-piece type uses two sets of rechargeable batteries 7, 8, which are installed therein and connected by wire 11. A control circuit board (not shown in the figure) selects one of the sets of rechargeable batteries to supply the motor. Since it is difficult to maintain equal capacities of the sets of rechargeable batteries 7, 8 in a charging process, the power-supply control unit in the charging unit, being a silicon assembly or a diode, will select the one with a higher capacity to supply the motor and prohibit mutual charging between the sets of rechargeable batteries 7, 8. Therefore, the operating time of the rechargeable vacuum cleaner is lengthened.

More specifically, the rechargeable vacuum cleaner of one-piece type is characterized by two sets of rechargeable batteries, one of which is used at one time to power the motor. Controlled by the technique of voltage dividing, the sets of rechargeable batteries are used alternatively, whereby the duration that the sets of rechargeable batteries are operating will be doubled.

The above said silicon assembly is a bridge rectifier capable of charging the sets of rechargeable batteries at the same time and preventing mutual charging between the sets of rechargeable batteries, because any reverse voltage higher than 50 V will activate the preventing effect. Therefore, the silicon assembly can be placed by a diode. The charging circuit also uses common linear or on/off transformers to charge the sets of rechargeable batteries.

Referring to FIGS. 8 to 11, the control printed circuit board (PCB) for both of the one-piece type and the twp-piece type is located at a predetermined location within the rechargeable vacuum cleaner. The power-supply control unit is located above the control PCB.

To summarize, a rechargeable vacuum cleaner of the present invention applies the technique of voltage dividing for lengthen its operating time. Since the conventional DC vacuum cleaners uses one set of battery to power the motor. To lengthen the operating time, some rechargeable vacuum cleaners use more than one set of batteries. The present invention uses a power-supply control unit to alternatively switch between the sets of rechargeable batteries for power the motor. Thereby, the operating time of the rechargeable vacuum cleaner can be further lengthened.

The present invention is thus described, and it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. 

1. A rechargeable vacuum cleaner, comprising: a main body; at least two sets of rechargeable batteries for driving a motor located within said main body; and a power-supply control unit coupled with said sets of rechargeable batteries and said motor for controlling said sets of rechargeable batteries powering said motor.
 2. The rechargeable vacuum cleaner of claim 1 wherein a positive terminal of said sets of rechargeable batteries is connected to one terminal of said motor through said power-supply control unit, and wherein a negative terminal of said sets of rechargeable batteries is directly connected to another terminal of said motor.
 3. The rechargeable vacuum cleaner of claim 1 further including a charging unit connected to said power-supply control unit, whereby said power-supply control unit will complete charging said sets of rechargeable batteries.
 4. The rechargeable vacuum cleaner of claim 3 further including a switch with one terminal connected to said negative terminal of said sets of rechargeable batteries and another terminal connected to a unit selected from said charging unit and said motor by switching between charging and discharging of said rechargeable batteries.
 5. The rechargeable vacuum cleaner of claim 1 wherein said power-supply control unit prohibits one of said sets of rechargeable batteries with higher electricity capacity charging another of said sets of rechargeable batteries with lower electricity capacity.
 6. The rechargeable vacuum cleaner of claim 1 wherein said power-supply control unit is selected from a silicon assembly and a diode.
 7. The rechargeable vacuum cleaner of claim 6 wherein said silicon assembly is a bridge rectifier.
 8. The rechargeable vacuum cleaner of claim 1 being a two piece structure having a main body and a detachable unit each equipped with a set of rechargeable batteries; said main body and said detachable unit are electrically connected by a connection port when united.
 9. The rechargeable vacuum cleaner of claim 1 wherein being a one piece structure having a main body equipped with said sets of rechargeable batteries. 